Readout Part Research Articles

Multi-reservoir echo state networks with sequence resampling for nonlinear time-series prediction

In this paper, we consider various schemes of sequence resampling in reservoir computing models for nonlinear time series prediction. These schemes can enrich the features used for training the readout part with batch learning and lead to better prediction performance. To implement these schemes, first, we introduce a modular approach for constructing multi-reservoir ESN models by assembling encoding and decoding modules. The encoding module is composed of a resampling unit, a group-wise reservoir unit, and a collection unit, for extracting various features from a sequence. The decoding module is a linear regressor which is trainable to produce desired outputs. Then, we propose three novel multi-reservoir ESN models, DeepESN with Every-layer Sequence Resampling (DeepESN-ESR), DeepESN with Last-layer Sequence Resampling (DeepESN-LSR), and GroupedESN with Input-layer Sequence Resampling (GroupedESN-ISR). These three models provide demonstrations of sequence resampling on multi-reservoir ESN models. Numerical results on five challenging nonlinear time-series prediction tasks show that the proposed models outperform some state-of-the-art multi-reservoir ESN models. An evaluation of computational time shows that our proposed three models require less computational cost for learning than many existing multi-reservoir ESN models in practice. Moreover, a comprehensive comparative analysis reveals that our proposed models are able to memorize longer temporal information and generate richer dynamics from the reservoir states than some existing models. The proposed schemes for extracting various features hidden in a sequence of reservoir states can be widely leveraged in other reservoir computing systems for improving their performance in nonlinear time series prediction.

Beam Monitors for Tomorrow: The Challenges of Electron and Photon FLASH RT

The emergent FLASH RadioTherapy (RT) uses ultrahigh dose-rate irradiation (up to 107 Gy/s instantaneous dose-rate in each μs pulse) to deliver a single high dose of irradiation in a very short time (less than 200 milliseconds). Pre-clinical studies at ultrahigh dose-rates recently showed an increased ratio between tumoricidal effect and normal tissue toxicity (therapeutic index), compared to conventional RT at standard Gy/min dose-rates. If confirmed by biological in vivo validations, this could represent a breakthrough in cancer treatment. However, the reliability and the accuracy of experimental studies are nowadays limited by the lack of detectors able to measure online the beam fluence at FLASH dose-rates. The behaviour of standard beam monitors (gas-filled ionization chambers) is compromised by the volume recombination caused by the amount of charges created per unit volume and unit time, due to the large dose-rate. Moreover, due to the lack of proper monitoring devices and to the uncertainties of its future applications, very few facilities are able to deliver at present FLASH irradiations. In this contribution, we report about the physical and technological challenges of monitoring high and ultra-high dose-rates with electrons and photon beams, starting from the pre-clinical and clinical constraints for new devices. Based on the extensive experience in silicon detectors for monitoring applications in RT with external beams, the work then investigates silicon sensors as a possible option to tackle such extreme requirements and a rugged thin and large (e.g. 10×10 cm2) flat detector (silicon-based sensor + readout electronics) is therefore outlined. This study aims at presenting the FLASH-RT dosimetry problem and analysing the possibilities for a silicon sensor to be employed as sensing device for several FLASH scenarios, including some ideas on the readout part. However, more detailed simulations and studies are demanded to delineate more precisely the technical choices to be undertaken in order to tackle the clinical accuracy required on the beam fluence, typically a few %, during photon and electron high and ultra-high irradiations, the required minimal perturbation of the beam and the high level of radiation resistance.

An innovative silicon photomultiplier digitizing camera for gamma-ray astronomy

The single-mirror small-size telescope (SST-1M) is one of the three proposed designs for the small-size telescopes (SSTs) of the Cherenkov Telescope Array (CTA) project. The SST-1M will be equipped with a 4 m-diameter segmented reflector dish and an innovative fully digital camera based on silicon photo-multipliers. Since the SST sub-array will consist of up to 70 telescopes, the challenge is not only to build telescopes with excellent performance, but also to design them so that their components can be commissioned, assembled and tested by industry. In this paper we review the basic steps that led to the design concepts for the SST-1M camera and the ongoing realization of the first prototype, with focus on the innovative solutions adopted for the photodetector plane and the readout and trigger parts of the camera. In addition, we report on results of laboratory measurements on real scale elements that validate the camera design and show that it is capable of matching the CTA requirements of operating up to high moonlight background conditions.

A Resonant Rolling Sphere Viscometer Using Magnetic Actuation and Readout

We present a viscosity measurement principle based on a metallic sphere rolling on a plane on a circular trajectory. The sphere is magnetically positioned and driven using a permanent magnet and four actuation coils placed below the rolling surface. This measurement principle is particularly suited for the characterization of thin fluid films and therefore also for cases where small sample volumes are available.We describe our prototype setup consisting of three parts: the probing body (sphere), the actuation part, and the readout part. For the readout two differential transformer arrangements are used, yielding a total of required five coils: one pair of readout coils for one direction and another pair perpendicular to it for the orthogonal direction. The fifth coil is used as primary coil in the differential transformer readout setup where the aforementioned coil pairs act as secondary coils.In this contribution we describe the sensor setup, outline the actuation and readout process and present first measurements.

Characterization of high resolution CMOS monolithic active pixel detector in SOI technology

Novel CMOS monolithic pixel detectors designed at KEK and fabricated at Lapis Semiconductor in 0.2 μm Silicon-on-Insulator (SOI) technology are presented. A thin layer of silicon oxide separates high and low resistivity silicon layers, allowing for optimization of design of detector and readout parts. Shallow wells buried under the oxide in the detector part screen the entire pixel electronics from electrical field applied to the detector. Several integration type SOI pixel detectors have been developed with pixel sizes 8–20 μm. The general features of 14 × 14 μm2 detectors designed on different wafers (CZ-n, FZ-n and FZ-p) were measured and compared. The detector performance was studied under irradiation with visible and infra-red laser, and also X-ray ionizing source. Using X-rays from an Am-241 source the noise of readout electronics was measured at different working conditions, showing the ENC in the range of 88–120 e−. The pixel current was calculated from average DC pedestal shift while varying the pixel integration time. The operation of the detector was studied under partial and full depletion conditions. The effects of temperature and detector bias voltage on noise and leakage current were studied. Characteristics of an ADC integrated in the front-end chip are also presented.

An Etch Stop and Sacrificial Materials Study for 3D NEMS-CMOS Co-Integration

In this paper, we compare several materials that can be used as sacrificial and etch stop layer for 3D NEMS-CMOS co-integration.During these last 10 years Very Large Scale Integration techniques, well developed for transistors, have been used for the M/NEMS world (Micro/Nano Electro-Mechanical Systems). This allowed the construction of various kinds of miniaturized nano-sensors, especially resonators that can be used for gas sensing, mass spectrometry and molecules recognition for example [1,2]. Nevertheless, the use of such nano-sensors requires a CMOS electronic circuit for the readout part and for the oscillating-loop creation with the nano-resonator. The CMOS part can be on a separated die linked to the NEMS resonator using wire bonding connections (Fig.1-a).However, in order to reduce signal transmission loss and allows the fabrication of a sensor with a high density of resonator, the best approach consists in processing both NEMS and CMOS on the same die (Fig.1-b and c) [3,4], in particular following a 3D scheme (Fig.1-c) [5,6]. The NEMS release process, commonly performed by a HF (Hydrogen Fluoride) vapor etching operation, is the final step of the integration. It implies the selection of two kinds of materials. The first one is a sacrificial layer in order to achieve a well-controlled and clean release of the mechanical structure. The second one is an etch stop layer located between the NEMS and CMOS for protecting all the area under the nano-resonator (Fig.2). In such 3D approach, etch stop and sacrificial layers can be deposited at high temperature before the molecular bonding of the mechanical part with the electronic part.Two parameters are critical for the selection of those materials; the etch rate and the presence and dimensions of the residues (see Fig.3, 4, 5 and 6) which may result from a silicon-fluorine complex precipitation during the etching process [7]. These residues must not disturb the mechanical resonator during its oscillations.This paper will present results about etch-rates and residual dimensions on HF vapor etching of materials used for the NEMS realization. It is shown in Fig.3 and Fig.6 that USG (Undoped Silicon Glass) and SiH4, usually used in back-end processes, are not suitable for the vapor HF release contrary to TEOS (tetraethyl-orthosilicate) Low Rate (LR) and boron-nitride (BN). Our study shows that the latter constitutes a good etch stop layer for HF vapor processing within a 3D integration scheme.[1] J. Arcamone et al, IEDM 2011 IEEE International, pp.29.3.1, 29.3.4, 5-7 Dec. 2011[2] Y.T. Yang et al, Nano lett., Vol. 6, No. 4, Apr. 2006[3] E.Ollier et al, MEMS 2012[4] J. Arcamone et al, Tech. Digest. IEDM 2012, pp. 15.4.1-15.4.4[5] P.Batude et al, J.Emerging Sel. Top.Circuits Syst, Vol.2, No.4, Dec. 2012[6] J-C. Souriau, IEEE Trans. Compon., Packag. Manuf. Technol. Vol. 1, No.6, June 2011[7] H. Ritala et al, ECS Trans. 2009 25(5): 355-358

Fundamental limitations in spin-ensemble quantum memories for cavity fields

Inhomogeneously broadened spin ensembles play an important role in present-day implementation of hybrid quantum processing architectures. When coupled to a resonator such an ensemble may serve as a multi-mode quantum memory for the resonator field, and by employing spin-refocusing techniques the quantum memory time can be extended to the coherence time of individual spins in the ensemble. In the present paper we investigate such a memory protocol capable of storing an unknown resonator-field state, and we examine separately the various constituents of the protocol: the storage and read-out part, the memory hold time with the spin ensemble and resonator field decoupled, and the parts employing spin refocusing techniques. Using both analytical and numerical methods we derive how the obtainable memory performance scales with various physical parameters.

SiPM application for a detector for UHE neutrinos tested at Sphinx station

We present the preliminary test results of the prototype detector, working at Sphinx Observatory Center, Jungfraujoch (~3800m a.s.l.) HFSJG – Switzerland. This prototype detector is designed to measure large zenith angle showers produced by high energy neutrino interactions in the Earth crust. This station provides us an opportunity to understand if the prototype detector works safely (or not) under hard environmental conditions (the air temperature changes between −25°C and −5°C). The detector prototype is using silicon photomultiplier (SiPM) produced by SensL and DRS4 chip as read-out part. Measurements at different temperature at fixed bias voltage (~29.5V) were performed to reconstruct tracks by Time Of Flight.

Modified read-out system of the beam phase measurement system for CSNS

The customized beam phase measurement system can meet the requirement of beam loss control of the radio-frequency quadrupole (RFQ). However, its read-out part cannot satisfy the requirement of China Spallation Neutron Source (CSNS). CSNS uses the Experimental Physics and Industrial Control System (EPICS) as its control system. So it is necessary to develop the EPICS read-out system consisting of EPICS IOC databases, driver support and OPIs. The new system has been successfully tested in the RFQ. In the future, it will be applied to the beam diagnostics of CSNS.

Qualitative and Quantitative Perfusion Parameters Determined by 3D Single-Shot GRASE ASL MR Imaging

Rationale and Objectives: A particular arterial spin (ASL) labeling technique, called 3D-single-shot GRASE ASL is discussed with respect to the ability and limits of quantifying perfusion parameters. Materials and Methods: The technique enables the acquisition of perfusion weighted signal at multiple delay times (TI) in one scan. The readout part is a gradient and spin-echo combination (GRASE) that uses switched gradient rephrasing of signals to produce several times as many signals as turbo-spin-echo, which translates into faster imaging time and higher signal-to-noise ratio (SNR) per imaging time. The technique provides the possibility for model based quantification of cerebral blood flow and the determination of the bolus arrival information without use of contrast agent and thus the characterization and determina-tion of regions that are supported by collaterals. Results: Whereas for a quantification of the permeability using ASL the SNR is not high enough, at least qualitative permeability maps can be determined, if an optimal homogenous SNR was guaranteed. This was accomplished in brain regions with a high blood supply, typically given in tumors, and by using a correction for coil sensitivity at the highest possible additional scaling. Conclusion: The single-shot 3D GRASE ASL can provide information about the principal blood supply, the transit delay of the blood flow due to a stenosis or collaterals and a qualitative measure of the permeability.

A DAQ system for CAMAC controller CC/NET using DAQ-Middleware

DAQ-Middleware is a framework for the DAQ system which is based on RT-Middleware (Robot Technology Middleware) and dedicated to making DAQ systems. DAQ-Middleware has come into use as a one of the DAQ system framework for the next generation Particle Physics experiment at KEK in recent years. DAQ-Middleware comprises DAQ-Components with all necessary basic functions of the DAQ and is easily extensible. So, using DAQ-Middleware, you are able to construct easily your own DAQ system by combining these components. As an example, we have developed a DAQ system for a CC/NET [1] using DAQ-Middleware by the addition of GUI part and CAMAC readout part. The CC/NET, the CAMAC controller was developed to accomplish high speed read-out of CAMAC data. The basic design concept of CC/NET is to realize data taking through networks. So, it is consistent with the DAQ-Middleware concept. We show how it is convenient to use DAQ-Middleware.

Test procedures for ALICE silicon pixel detector ladders

ALICE is one of the experiments which are about to start data taking at the CERN Large Hadron Collider (LHC). It consists in an assembly of detectors aimed at allowing a complete and precise reconstruction of a typical heavy-ion collision event. Its innermost sensitive elements are two layers of silicon pixel detectors (SPD), each one consisting of a 200 μ m silicon sensor bump bonded to five electronic readout chips subdivided into 8192 ( 32 * 256 ) elementary cells. The SPD is fundamental to obtain a precise estimation of the particle momenta. It will also allow to estimate the position of primary and secondary vertices (which are important for study of heavy quarks) and to evaluate the event multiplicity before tracking. Before integration in ALICE, each sensitive and electronic readout part of the SPD must pass through a sequence of tests which ensure constant production quality, in all its operational aspects (electronic control and response, data acquisition performance and thresholds). This presentation describes the test procedure for single electronic readout chips before and after they have been bump bonded to the silicon sensors.

A low-cost and highly integrated fiber optical pressure sensor system

This paper presents a simple, affordable, fiber-optic based pressure measurement system, in which both sensor and readout parts are constructed using batch micromachining techniques, supplemented with some straightforward assembly steps. Prototypes of relative and absolute pressure sensors parts and a readout part have been realized. Goal of this research is to enable deployment of such harsh-environment sensors in high-volume, low-cost applications.

Integrated conditional teleportation and readout circuit based on a photonic crystal single chip

We demonstrate the design of an integrated conditional quantum teleportation circuit and a readout circuit using a two-dimensional photonic crystal single chip. Fabrication and testing of the proposed quantum circuit can be accomplished with current or near future semiconductor process technology and experimental techniques. The readout part of our device, which has potential for independent use as an atomic interferometer, can also be used on its own or integrated with other compatible optical circuits to achieve atomic state detection. Further improvement of the device in terms of compactness and robustness could be achieved by integrating it with sources and detectors in the optical regime.

Full-size monolithic active pixel sensors in SOI technology—Design considerations, simulations and measurements results

The paper addresses development of full-size monolithic active pixel detectors exploiting silicon-on-insulator (SOI) technology for the integration of a radiation detector and readout electronics in one entity. A general overview of the sensor design is presented and then considerations of the interaction between the readout and sensitive part of the SOI active sensor are discussed. The layout solution used in the design of the full-size prototypes to overcome the problem of the crosstalk between the readout electronics and the detector are reported. Preliminary measurements results of the first full-size prototypes of SOI sensors are also reported.

Overview of the ECAL off-detector electronics of the CMS experiment

Located between the on-detector front-end electronics and the global data acquisition system (DAQ), the off-detector electronics of the CMS electromagnetic calorimeter (ECAL) is involved in both detector readout and trigger system. Working at 40 MHz, the trigger part must, within ten clock cycles, receive and deserialize the data of the front-end electronics, encode the trigger primitives using a nonlinear scale, assure time alignment between channels using a histogramming technique and send the trigger primitives to the regional trigger. In addition, it must classify trigger towers in three classes of interest and send this classification to the readout part. The readout part must select the zero suppression level to be applied depending on the regions of interest determined from the trigger tower classification, deserialize front-end data coming from high-speed (800 Mb/s) serial links, check their integrity, apply zero suppression, build the event and send it to the DAQ, monitor the buffer occupancy and send back pressure to the trigger system when required, provide data spying and monitoring facilities for the local DAQ. The system, and especially the data link speed, the latency constraints and the bit-error rate requirements have been validated on prototypes. Part of the system is about to go to production.

The coincidence matrix ASIC of the level-1 muon barrel trigger of the ATLAS experiment

The ATLAS barrel level-1 muon trigger processes hit information from the resistive plate chamber detector, identifying candidate muon tracks and assigning them to a programmable p/sub T/ range and to a unique bunch crossing number. The trigger system uses up to seven detector layers and seeks hit patterns compatible with muon tracks in the bending and nonbending projection. The basic principle of the algorithm is to demand a coincidence of hits in the different chamber layers within a path. The width of the road is related to the p/sub T/ threshold to be applied. The system is split into an on-detector and an off-detector part. The on-detector electronics reduces the information from about 350 k channels to about 400 32-bit data words sent via optical fiber to the so-called sector logic (SL). The off-detector SL electronics collects muon candidates and associates them to detector regions-of-interest of /spl Delta//spl eta//spl times//spl Delta//spl Phi/ of 0.1/spl times/0.1. The core of the on-detector electronics is the coincidence matrix ASIC (CMA), which fulfils both the trigger algorithm and the readout of the RPC detector. Each CMA is able to process and readout 192 RPC strips from as many as four detector layers. In order to keep the full level-1 system latency below 2 /spl mu/s, the CMA has to find candidate muon tracks with a latency of a few 25 ns bunch crossing periods. The readout part of the CMA is able to time tag incoming RPC hits with a time interpolator running at the trigger pipeline frequency of 320 MHz and to send the data to the readout system via a serial link. The design of the trigger system and the performances of the ASIC, based on a CMOS 0.18 /spl mu/m technology, are presented.

Physical aspects of detector design

A new generation of digital radiation detectors is described which is based on solid state technology. The detector front-end consists of two stages, the conversion and the readout part. For the conversion stage there are two different concepts: direct conversion using heavy semiconductor layers, or indirect conversion by combination of scintillators and photodiodes. The readout stage is based on amorphous silicon large-area technology and charge sensitive readout amplifiers. In this paper the properties of different detector materials, system aspects of detector design, and the impact of physical properties on image quality are discussed.

Design and performance of the fermilab E781 (SELEX) hardware scattering trigger

The design and performance of the Fermilab E781 (SELEX) Hardware Scattering Trigger (HST) are described. This trigger functioned by distinguishing beam scattering at small angles ( >150 μ rad) from non-interacting beam. Six 50 μ m pitch silicon planes grouped in three ( x, y) stations, two before and one after the target, were used as the particle detectors. The triggering system involved 1920 channels of readout providing data to the Fast Encoding and Readout System (FERS) with programmable trigger logic processor. The overall system was tested successfully at Fermilab during the 1996-1997 fixed target run. The encoding time of the readout part of the FERS device was 30 ns and the processor decision time was 55 ns. The HST provided an output signal 250 ns after beam traversal of the target.